• We report the first known case of septicemia caused by Saccharomyces cerevisiae. It occurred nosocomially in a hyperalimented burned man. It is a rare example of disease caused by S cerevisiae, which, like many saprophytes, can become pathogenic in the debilitated. The case is remarkable for its apparent origin in a bleeding esophageal lesion, for its clinical character istics, including profound neutropenia, thrombocytopenia, hypothermia, and monocytopenia, and for its cure by amphotericin B.